If the Circumference is 6 ft. What is the radius?  

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academicsfirst's profile pic

academicsfirst | High School Teacher | (Level 2) Adjunct Educator

Posted on

We are given the circumference of a circle.  We are asked to find the radius.


We will use the formula Circumference = 2pi(radius)

=> C=2pi(r)

=> Substitute 3.14 for pi, and 6 for C

=> 6 = 2(3.14)r

=> 6 = 6.28r

=>  .955 =r

=>  The radius is approximately .96 ft.

taangerine's profile pic

taangerine | Student, Grade 12 | (Level 1) Valedictorian

Posted on

What we know: 

  • C= `2pir`
  • C=6 ft
  • `pi=3.14`

Combine first 2 equations. 

  • `6=2pir`

Divide `2pi` on both sides. 

  • `((6)/(2pi))=r`

Simplify

  • r=`3/pi ft`
michaelcoffey's profile pic

michaelcoffey | College Teacher | eNotes Newbie

Posted on

First, divide the given circumference by 3.14 to get the diameter.

6/3.14=1.91

Second, Divide the answer by 2 to get the radius.

1.91/2 = .955

sweetteach's profile pic

sweetteach | Teacher | eNotes Newbie

Posted on

To find the radius of a circle using the given circumference we use the formula for finding Circumference.

C=2pi(r)

Using 3.14 for pi and 6 for the Circumference, we solve for r (radius).

6=2(3.14)r     (multiply 2 times pi)

6=6.28r         (divide each side of the equal sign by 6.28)

r≈.955           (the result is that r is approximately .955)

Rounding to the nearest hundredths place the radius is about .96 ft.

 

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